Misleading clinical presentation of carcinoid syndrome

Abstract

Rare cases of carcinoid syndromes can develop from either gastrointestinal neuroendocrine tumors (NETs) without liver metastasis or large retroperitoneal involvement. We report a case of a patient with isolated flushing highly suggestive of carcinoid syndrome caused by an ileal NET with adjacent lymph node metastases but with no liver metastases. The final diagnose was delayed for this patient due to a combination of misleading clinical presentation and negative usual screening tests (urinary 5-HIAA and serum chromogranine A). Given its high sensitivity and specificity, ⁶⁸Ga-DOTATATE PET/CT confirmed the diagnosis of neuroendocrine tumor. Therefore, this case reminds clinicians that carcinoid syndrome may manifest as flushing only and highlights that imaging is a major aspect of the evaluation and diagnosis of patients with suspected gastrointestinal NETs.

Keywords: 5-HIAA; ⁶⁸Ga-DOTATATE PET/CT; carcinoid syndrome; chromogranin A; flushing; neuroendocrine tumors (NET).